Kitchen Extensions South Kensington

A kitchen extension in South Kensington is usually a question about a terraced house, because 13% of homes here are terraces and only 2% are semi-detached or detached. The housing is old: 84% of all homes here were built before 1919. The typical job is a modest single-storey addition at the back of a tall period house, built into a garden overlooked by every neighbour on the row. It is planned around the rear building line and the conservation areas, which cover more than 73 per cent of the borough.

In South Kensington, a rear kitchen extension of about 30 square metres typically costs £45,000 to £97,500 excluding VAT, or £60,000 to £100,000 for a side return (indicative London ranges, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in South Kensington: the structural engineer we appoint designs the foundations and steel, we build the room and fit the kitchen, and a registered electrician certifies the electrics.

How far back a South Kensington kitchen can go

The depth is set first by what the neighbours already have. Policy CL9 of the Consolidated Local Plan resists an extension that would project rearward beyond the existing general rear building line of neighbouring extensions. On a South Kensington terrace that means standing in the garden and reading the backs of the next few houses before anyone draws a plan. If the adjoining closet wings stop at a common line, the new kitchen is designed to stop there too.

That test shapes the room more than the budget does. Where the line is shallow, the extra space has to come from width or from the rooms you already have: infilling the space beside a closet wing, or opening the back reception into the kitchen. Your designer tests those options against the line, and we price each one so you can compare the space gained against the structural work and the disruption each option involves.

Housing in South Kensington

South Kensington has around 8,840 homes on the Council Tax list: 12% post-war, 3% interwar and 84% predate 1919, with 85% flats and 15% houses. Most homes here are flats, and only a ground floor flat in South Kensington with its own garden can extend its kitchen.

South Kensington conservation areas and the limits of permitted development

Check the designation before assuming permitted development. The borough's New Local Plan Review states that conservation areas cover more than 73 per cent of the borough, and national rules say every side extension on designated land such as a conservation area needs householder planning permission. That catches a side return infill. The Brompton Conservation Area Appraisal also names oversized rear extensions among the negative elements harming that area, which is the language a scheme there has to answer.

A design that answers those concerns is usually a low, subordinate addition in brick or render that matches the house, with the glazing concentrated in the roof and the rear face rather than a full width box. That affects the programme: the drawings, the heritage statement and the decision come before we order steel or glazing. We build to the approved drawings and flag any site change to your designer before it is made, so the consent is not put at risk halfway through.

Flats and houses have different starting points

If you own a garden flat rather than a whole house, there are no householder permitted development rights to use at all. National guidance is explicit that the householder extension rules apply to houses only and not to flats and maisonettes. With 85% of homes in South Kensington being flats, the kitchen you want to extend may well be in a lower ground floor flat with a garden, and that needs a full planning application whatever its size.

A flat also brings the freeholder into the job. The lease commonly reserves the external walls and the garden, so a licence to alter is needed before the rear wall is opened, and the managing agent will want to see the method and the working hours. We give you the drawings, programme and method statement the agent asks for, so the licence can be drafted around the real scope before any work starts on site.

Drainage, steel and the back of a tall South Kensington house

The heavy work sits where the new kitchen meets the old house. Opening the rear wall of a tall period terrace means a steel frame or beam carried on padstones, sized by the structural engineer we appoint and checked by building control before the wall is cut. Temporary propping stays in until the steel is packed and seated, and the floors above are watched for movement as the load transfers onto the new bearings.

Drainage is the other early question. Terraces of this age can have a shared run along the backs of the houses, and a new kitchen floor can land on top of it. We open up and survey the run before the slab is designed, so the sink, dishwasher and any floor gully fall to a working connection. Where a public sewer lies under the footprint, the water company's build over process is started early so it does not hold up the groundworks.

• Utility rooms and larders at the back of the extension
• Boiler relocation and flue changes on the enclosed rear wall
• The kitchen itself fitted under the same contract as the build

VOA Council Tax stock of properties, March 2025, for South Kensington and Queen's Gate. Counts rounded by the VOA.

For the wider picture around kitchen extensions in South Kensington, see kitchen renovation in South Kensington, kitchen extensions across Kensington and Chelsea, fitting the kitchen itself, how building control inspects an extension, kitchen extensions across London and Bifold or Sliding Doors.

The GS Renovation Difference in South Kensington

We run the extension and the kitchen as one programme, so the steel, drainage, glazing, electrics and units follow each other without a gap between two firms. The structural engineer we appoint sizes the steel, a registered electrician certifies the circuits, and building control inspects each stage. We work from your designer's approved drawings, give the managing agent or neighbours the programme and method they ask for, and keep noisy work to the hours the council sets. You get one written scope, one programme and one team on site.

• New floor level matched to the existing house, with no step at the opening
• Materials priced at options, so you choose the finish
• Screed left to dry before the kitchen floor finish goes down

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254). Structural design is by the consulting engineer appointed to your project.